“It was a real-life horror story,” Michaels told AFP. “It involved bright, young, glamorous people — it just had all the elements and was the first big criminal case that people became obsessed with.

“It scared the hell out of Los Angeles. The whole city was on edge and then they discovered that the people who did it were just kids. It just continued to shock right the way through the trial,” he added.

The details of the killings have lost none of their shock capacity with the passage of time.

Manson, portrayed at his trial as a drug-crazed loner with mesmerizing powers of persuasion, ordered devotees to carry out random killings in wealthy white neighborhoods in an effort to trigger an apocalyptic race war.

Though the Manson family was responsible for at least nine murders, it is the seven lives claimed during the rampage in Los Angeles between August 9 and 10, 1969 with which the group is most closely associated.

Among the victims was the movie actress Sharon Tate, the 26-year-old wife of director Roman Polanski and eight-and-a-half months pregnant at the time, stabbed to death as she pleaded for the life of her unborn child.

Tate died along with four others at her home in the Hollywood Hills after four Manson disciples — henchman Charles “Tex” Watson and three women, Susan Atkins, Patricia Krenwinkel and Linda Kasabian, struck.

Using a towel dipped in Tate’s blood, Atkins daubed the word “Pig” on the front door of the home. The next night, Manson and six others struck at the home of businessman Leno LaBianca, killing him and his wife Rosemary.

British journalist Ivor Davis, whose book “Five to Die” is being reissued to coincide with the anniversary, agrees with the suggestion that the Manson killings were “the day the Sixties died.”

“It was the time of Haight-Ashbury, Woodstock, love and peace, hug your neighbor, go to bed with your neighbor, fornicate with your neighbor,” Davis told AFP. “And then Manson came along and it was murder your neighbor.
“The terrible thing that happened at the Tate house not only killed all those people, it killed a generation really — a whole mood, an atmosphere,” said Davis, who covered the murders and the subsequent trial.

Former Los Angeles District Attorney Vincent Bugliosi, who prosecuted the Manson family and co-authored “Helter Skelter,” an exhaustive, best-selling account of the crimes, said the savagery of the murders fueled the panic.

“I’ve heard many people say that prior to these murders, there were areas of the city where folks literally did not lock their doors at night,” Bugliosi told Newsweek magazine. “That ended with the Tate/LaBianca murders.
“The killings were so terribly brutal and savage: 169 stab wounds, seven gunshot wounds. They appeared to be random with no discernible conventional motive. That induced a lot of fear throughout the city,” he added.

Although police initially failed to link the two sets of murders, Manson and four followers — Atkins, Watson, Krenwinkel and Leslie Van Houten — were eventually convicted of murder and sentenced to death. Kasabian, who had been at the Tate house, was the star witness and granted immunity.

The death sentences were commuted to life in prison after California briefly outlawed capital punishment. Since then, Manson, 74, and his fellow convicts have repeatedly sought parole but have been rejected.

Atkins, 61, who has brain cancer, had a request for compassionate release denied in July last year and is due to make another bid at a hearing in Los Angeles on September 2.

The repeated parole hearings, a 2008 search for human remains at Manson’s former Death Valley hideout and the power of the Internet have ensured longevity for the Manson murders.

“Every year or so, one of them comes up for parole and the whole story gets regurgitated,” Davis said. “The Internet has been an incredible driving force. It’s kept the Manson myth bubbling along.”

According to Michaels, Manson’s status as “America’s boogeyman” makes it unlikely that any of those associated with the crimes will ever be released.

“They were sentenced to die in the gas chamber and they were lucky to have those sentences commuted,” he said. “That was more mercy than they showed any of their victims. Maybe this is an occasion when life should mean life.”